There is a suspenseful lull in the Rencontres, the annual festival of photography that takes place at Arles in the south of France every year. Francois Hébel, the long-standing director, is taking his bow this year and his successor, Sam Stourdzé, who made a great success of his tenure at the Musée de l’Elysée in Lausanne, is poised to take over.

IN Visual Arts

The festival is smaller, a bit hesitant, a bit diminished. Is it recoiling before a greater spring forward, or is the end of the director’s tenure the end also of an era?

The change is not merely one of personnel. The great railway engineering sheds on the outskirts of town, which have been a vibrant festival location in recent years, no longer belong to the city of Arles and are due to be rebuilt by Frank Gehry for Maja Hoffmann’s Luma foundation. The sheds are only partially available to the festival this year, and the sense of loss is as palpable now the cultural hubbub has gone as it must have been when the works were closed down. Inescapably, the old guard of the Rencontres, rooted in humanist photography and in documentary, feels apprehensive at the prospect of change, change that may well head to an event less rooted in photography and more cross-cultural, even conceptual, than the old-fashioned photo-people are used to or like.

Hébel, not surprisingly, has looked back in his swansong. Leading curators from past years have been invited to try again, with mixed results. Somebody had the foolish idea of mounting a group of shows in an empty office building in the dark, with visitors handed a light on the way in. None of those shows can be properly reviewed as a result.

There are, even in a diminished year, too many shows to cover equally. One church hosts a likeable show of Vik Muniz’s Album pictures, massive collages depicting family scenes that are themselves made from family-album pictures, hundreds of them. The effect is to show people swimming through a host of memories even as they create the new memorable moments of their own lives. Muniz mines existing pictures to make new ones.

And that may be the theme of the year. Re-using pictures that have had a previous life is astonishingly common at the moment, and there is an explanation.

In a world where it’s as easy to make and send a picture as it now is, there is considerable suspicion of the photographer. What has she done that I can’t do? What’s special about that? Photographers have resorted to a number of tricks simply to distinguish themselves from amateurs. Huge and expensive prints; fancy framing surfaces like Diasec; self-published books ... These tricks are decreasingly effective, though. Selecting pictures is now a more satisfactory sign of discrimination than making them. And size, by the way, is no longer an issue. Outsize pictures at last look like what they always were, a too- desperate attention to hog the wall and the eye. Small is beautiful and is back.

WM Hunt is an American collector whose discrimination is widely lauded after the success of his The Unseen Eye, a popular show at Arles a few years ago. Invited back, he has chosen to show a vast number of those group pictures in which everybody lines up to represent the team, the regiment, the works, the school or the Rotary club. This unpromising material produces sheer curatorial gold.

Selecting pictures is now a more satisfactory sign of discrimination than making them

The central point is that to fall into Hunt’s hands at all, these pictures have to have lost their primary meaning. In September 1935 a lot of young women lined up in bathing costumes for the Inter City Beauties – Showmen’s Variety Jubilee on the Steel Pier in Atlantic City. We know they did; we can see them, some coy, some gleeful, standing on trestle tables covered in cheap cloth. As individuals, we can no longer know who they were: what survives is the collective identity only. The assembled staff of the National School of Aeronautics in Kansas City were photographed in 1943 – for some reason – on their knees in a park. They wear baggy shorts and a quite surprisingly large number of them wear glasses. Why? Who thought it a good marker of their corporate identity to make them look like myopic dwarves?

Beyond quirkiness and charm and small history and the pleasure of the curious associations that people choose to band themselves in, there are two reasons these pictures achieve their effects. The first is that they are absolutely crammed with detail. Group shots are by definition planned in advance. That means that they were done with large cameras in good light and controlled conditions. To peer at them is to be rewarded with ever greater detail, and the pleasure of doing so is irresistible.

The second reason is that they are (nearly all) panoramic in format, and so the eye is unable to grasp that frameful of information in one go. Viewers have to scan them, seeking out details, backtracking. So each viewer spends far longer on each picture than is usual. There is a corresponding sense of concentration, and a corresponding reward in the harvest of details to be read. One or two of the Ku Klux Klansmen in one image, for example, had evidently left their hoods at home on the day of the picture and put table napkins on their heads instead.

Hunt is not the only collector with holdings on show in Arles. Another is Artur Walther, whose collection is famous and very wonderful but normally lives in a private museum in Germany. It’s well published, so not particularly new. But moving a chunk of it to Arles is a generous kindness. And what a chunk. Complete series of Sander and the Bechers and Zhang Huan, and Dieter Appelt, and lots of other people, well displayed so that each one raises questions about the one opposite.

Since the photographers chosen work in series, they are in effect collectors themselves. So Walther is a collector of collectors. There’s postmodernism for you! Don’t miss the show. It’s a treasure house. The few disappointments (like some dreadfully too large prints by Ai Weiwei) are revealing, and the masterpieces outnumber them many times over.

There are plenty of other shows worth catching. One is a group show curated by Erik Kessels, a Dutch collector of vernacular photography, which tries to tackle what it means to work in series, and why people are compelled to do it. The images range from the hilarious to the self-effacingly sober. In the former camp is a conceptual artist called Hans Eijkelboom, who managed in 1973 to photobomb every day for a fortnight the picture used by De Nieuwe Krant newspaper. He just lurked about, in shot. In the latter is the typologist Jos Houweling, also in Amsterdam, also in the 1970s, who photographed the overlooked bits of street equipment, from cast-iron drain covers to those canvas covers people tie on their cars.

The moral of the story is not very complicated: photography, responding to the massive changes brought about by digital technology, is still a bit in retreat. While that goes on, the impulse to re-examine what it has already done is very strong. It’s looking over its shoulder for a while – and so is the festival at Arles.